Tool profile automatic graphic display system

ABSTRACT

A tool profile automatic graphic display system according to the invention includes memory means (6) for storing a conversational-type machining program and a tooling file used as tool data, data input means (3) for inputting machining data, control means (1) for selecting an optimum tool in dependence upon specified machining data relating to a machining region and machined profile of a workpiece, and graphic display means (4) for graphically displaying the profile of a selected tool, the graphic display means (4) graphically displaying a tool profile along with a blank profile and machined profile automatically.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates to a tool profile automatic graphic displaysystem for automatically describing the profile of a tool used when aworkpiece is to be machined into a predetermined shape based on aconversational-type machining program using e.g. a computer-controlledNC lathe.

2. Description of the Related Art

In order to fabricate a workpiece having a complex, elaborate structurein cases where the machining is performed by a machine tool such as acutter, drill or milling machine, positional coordinates are decidedusing e.g. a keyboard and display, and machining data (a program commandtape) for numerical control (NC) are prepared. An NC unit numericallycontrols the machine tool on the basis of the machining data on thecommand tape to subject the workpiece to the desired machining.

In machining of this kind, the tools used naturally differ dependingupon the type of machining, e.g. drilling and planar machining.Moreover, even for the same planar machining operation, cutting tools ofvarious shapes are prepared and are used accordingly depending upon theshape to which the workpiece is to be cut and the region machined. Tofacilitate tool selection at such time, a CNC (computer NC) has beendeveloped to enable the programming of NC data in accordance withdrawings in a conversational mode of operation while the profile of aworkpiece blank and the profile into which the workpiece blank is to bemachined are displayed on a graphic display. With an NC unit of thiskind, machining data are specified to create the machining programautomatically. A list of tools prepared on the machine tool side iscreated in advance and the tools best suited for the workpiece materialor region to be machined are then selected automatically. Since suchcutting conditions as revised values of velocity and depth of cut whichprevail when a selected tool is driven into operation change, the usualpractice is to prepare files of plural cutting conditions, graphicallydisplay a tool trajectory in accordance with the file corresponding tothe selected tool, and then decide the machining data.

When a machining drawing is complicated, however, the associated cuttingrequirements change frequently. Consequently, though the operator iscapable of freely specifying the tools and regions to be machined, skillis required for such an operation. If it were attempted to decide all ofthe machining steps automatically by employing a function for suchpurpose, it would not be possible to check sufficiently for interferencebetween the selected tool and a chuck or tool stock by relying solelyupon the graphic display of the tool trajectory. The problem that wouldresult is issuance of an alarm when the NC unit is operated by amachining tape or the like using the machining data that have beenprepared.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a tool profileautomatic graphic display system capable of automatically portraying atool profile along with a blank profile and machined profile when a toolis selected by utilizing a tooling file storing tool data, therebymaking it possible to select the most suitable tools and readily createthe appropriate NC machining tape.

The tool profile automatic graphic display system of the presentinvention includes memory means for storing a conversational-typemachining program and a tooling file used as tool data, data input meansfor inputting machining data, control means for selecting an optimumtool in dependence upon specified machining data relating to a machiningregion and machined profile of a workpiece, and graphic display meansfor graphically displaying the profile of a selected tool, the graphicdisplay means graphically displaying a tool profile along with a blankprofile and machined profile automatically.

More specifically, in order to create NC command data in accordance withthe present invention, a graphic display of the tool profile isperformed by calling data for graphically displaying the profile of theselected tool from a memory in which the necessary data have beenregistered, and then specifying the required parameters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view illustrating an example of a tool profilegraphic display in accordance with the present invention;

FIG. 2 is a block diagram showing an embodiment of the presentinvention;

FIG. 3 is an explanatory view showing an example of a tooling file fordeciding an optimum tool; and

FIGS. 4(a) through 4(d) are explanatory views showing examples ofsetting coordinates for graphic display of a tool profile.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will now be described in detailwith reference to the drawings. As shown in FIG. 2, an NC unit whichuses a microprocessor to process a machining program for selecting andcontrolling the drive of a prescribed tool such as a cutter includes adata input unit 3 such as manual data input unit (MDI), a display unit 4such as a CRT, a program memory 5, a data memory 6 storing tool data andthe like, and a controller 8 for controlling the drive shaft of amachine tool 7, all of which are connected to a bus 2 of the CPU 1.

FIG. 3 illustrates an example of a tooling file. When an operatormachines a workpiece into a predetermined shape based on aconversational-type machining program using an NC unit of the abovetype, the tooling file makes it easy to decide the optimum tool by beingdisplayed for the operator on the display unit 4.

The arrangement is such that such necessary data as tool type, tool noseradius, cutter angle, tool nose angle, tool nose protection angle,imaginary tool nose position, holder diameter, type of process, toolselection number, tool revision number, mounting angle, mountingposition and X mirror image can be set in the tooling file.

FIG. 1 illustrates an example of a tool profile 10 displayed in an X-Zcoordinate plane at the same time as a blank profile (dashed line) andmachined profile (solid line).

A common procedure in automatic programming includes first selecting acoordinate system, then inputting the blank profile and its dimensions,inputting the machined profile and its dimensions, and thereafterselecting a tool. The tool profile 10 displayed as shown in FIG. 1 is anexample of a cutting tool, wherein the cutting angle (AC=α), tool noseangle (AN=β) and mounting angle (AS=γ) are defined as illustrated. Whena parameter l, representative of cutting surface length, is specifiedwith the position of the tool nose aligned with the origin of thecoordinate system, points A (X₁,Z₁), B (X₂,Y₂) can be calculated usingthe following equations:

    X.sub.1 =-m sin (γ-α)

    Z.sub.1 =-m cos (γ-α)

    X.sub.2 =-m sin (γ-α-β)

    Z.sub.2 =-m cos (γ-α-β)

where m=l/|cos (β/2)|

Accordingly, by inputting a tool number or revision number andspecifying the parameter l, cutting angle, tool nose angle and the likeon the display screen, the tool profile is displayed automatically. Thismakes it possible for the operator to readily find any designated toolinterference, the uncut portion of the workpiece and the like.

FIGS. 4(a) through 4(d) illustrate examples of coordinate systemsettings for graphically displaying the profiles of a button tool,grooving tool, corner removing tool and drilling tool, respectively.

In the case in the button tool of FIG. 4(a), the tool profile to bedisplayed is described on the screen by defining the cutting angle(AC=α), tool nose angle (AN=β), mounting angle (AS=γ) and tool noseradius (Rn=r). The points R (X₀,Z₀), A(X₁,Z₁), B(X₂,Z₂), C(X₃,Z₃) whenthe position of the tool nose is aligned with the origin are calculatedby using the following equations:

    X.sub.0 =-r sin γ

    Z.sub.0 =-r cos γ

    X.sub.1 =2X.sub.0

    Z.sub.1 =2Z.sub.0

    X.sub.2 =-r(sin γ-cos γ)

    Z.sub.2 =-r(cos γ+sin γ)

    X.sub.3 =-r(sin γ+cos γ)

    Z.sub.3 =-r(cos γ-sin γ)

For the grooving tool and corner removing tool of FIGS. 4(b) and 4(c),the tool profiles to be displayed are described on the screen bydefining the cutting angle (AC=α), tool nose angle (AN=β), mountingangle (AS=γ), groove width (Wn=w) and parameter l. The points A (X₁,Z₁),B(X₂,Z₂), C(X₃,Z₃) when the position of the tool nose is aligned withthe origin are calculated by using the following equations:

    X.sub.1 =-l sin (γ-α-β)

    Z.sub.1 =-l cos (γ-α-β)

    X.sub.2 =X.sub.1 +X.sub.3

    Z.sub.2 =Z.sub.1 +Z.sub.3

    X.sub.3 =-w sin (γ-α)

    Z.sub.3 =-w cos (γ-α)

For the drilling tool of FIG. 4(d), the tool profile to be displayed isdescribed on the screen by defining the drill radius (DD=α), tool noseangle (AN=β), mounting angle (AS=γ) and the parameter l. The points A(X₁,Z₁), B(X₂,Z₂) when the position of the tool nose is aligned with theorigin are calculated by using the following equations:

    X.sub.1 =-m sin (γ+β/2)

    Z.sub.1 =-m cos (γ+β/2)

    X.sub.2 =-m sin (γ-β/2)

    Z.sub.2 =-m cos (γ-β/2)

where m=l/|cos (β/2)|

Thus, tool selection is carried out with ease by incorporating a programwhich, when a conversational-type machining program is executed, selectsan optimum tool from the abovementioned tooling file and displays thetool profile together with the workpiece, as shown in FIG. 1, by meansof the display unit 4.

In accordance with the automatic graphic display system of the presentinvention, a tool profile can be displayed automatically along with theblank profile and machined profile at the time of tool selectionutilizing a tooling file storing tool data. This makes it possible toselect the optimum tool and readily prepare a suitable NC machiningtape.

What is claimed is:
 1. A tool profile automatic graphic display systemfor automatically displaying a profile of a tool used when a workpieceis to be machined into a predetermined shape based on aconversational-type machining program, said system comprising:memorymeans for storing a conversational-type machining program and a toolingfile containing tool data, including a mounting angle and a tool noseangle for all tools, a cutting angle and a tool nose radius for buttontools, the cutting angle, a groove width and a cutting surface lengthfor grooving and corner removing tools and a drill radius and thecutting surface length for drilling tools, all relating to profiles ofrespective tools; data input means for inputting machining data,including a machined profile of the workpiece, and tool identificationdata; control means for selecting an optimum tool in dependence upon thetool data in the tooling file together with specific machining datarelating to a machining region of the machined profile of the workpiece;calculating means for calculating tool profile graphic display data independence upon the tool data relating to the profile and the mountingangle of the tool contained in the tooling file stored in said memorymeans; and graphic display means for graphically displaying the machinedprofile of the workpiece simultaneously with the profile of the optimumtool in dependence upon the tool data in the tooling file.